This invention relates to medical apparatus, and more particularly to apparatus for use in making anastomotic connections between tubular body fluid conduits in a patient.
There are many medical procedures in which it is necessary to make an anastomotic connection between two tubular body fluid conduits in a patient. An anastomotic connection (or anastomosis) is a connection which allows body fluid flow between the lumens of the two conduits that are connected, preferably without allowing body fluid to leak out of the conduits at the location of the connection. As just one example of a procedure in which an anastomosis is needed, in order to bypass an obstruction in a patient""s coronary artery, a tubular graft supplied with aortic blood may be connected via an anastomosis to the contrary artery downstream from the obstruction. The anastomosis may be between the end of the graft and an aperture in the side wall of the coronary artery (a so-called end-to-side anastomosis), or the anastomosis may be between an aperture in the side wall of the graft and an aperture in the side wall of the coronary artery (a so-called side-to-side anastomosis (e.g., as in published Patent Cooperation Treaty (xe2x80x9cPCTxe2x80x9d) patent application WO 98/16161, which is hereby incorporated by reference herein in its entirety)). The graft may be natural conduit, artificial conduit, or a combination of natural and artificial conduits. If natural conduit is used, it may be wholly or partly relocated from elsewhere in the patient (e.g., wholly relocated saphenous vein or partly relocated internal mammary artery). Alternatively, no relocation of the graft may be needed (e.g., as in above-mentioned application WO 98/16161 in which a length of vein on the heart becomes a xe2x80x9cgraftxe2x80x9d around an obstruction in an immediately adjacent coronary artery). More than one anastomosis may be needed. For example, a second anastomosis may be needed between an upstream portion of the graft conduit and the aorta or the coronary artery upstream from the obstruction in that artery. Again, this second anastomosis may be either an end-to-side anastomosis or (as shown, for example, in above-mentioned application WO 98/16161) a side-to-side anastomosis. Alternatively, no second, upstream anastomosis may be required at all (e.g., if the graft is an only-partly-relocated internal mammary artery).
The currently most common technique for making an anastomosis is to manually suture the two tubular body fluid conduits together around an opening between them. Manual suturing is difficult and time-consuming, and the quality of the anastomosis that results is highly dependent on the skill of the person doing the suturing. In the case of coronary artery bypass procedures, one source of difficulty for suturing of an anastomosis may be motion of the heart. There is also increasing interest in procedures which are less invasive or even minimally invasive. Such procedures have potentially important advantages for patients, but they may increase the difficulty of performing manual suturing of an anastomosis by reducing or limiting access to the site within the patient at which the anastomosis must be made. Various examples of such less invasive or minimally invasive procedures are shown in above-mentioned application WO 98/16161, Goldsteen et al. U.S. Pat. No. 5,976,178, Sullivan et al. U.S. Pat. No. 6,120,432, published PCT patent application WO 98/55027, and Berg et al. U.S. patent application Ser. No. 09/187,364, filed Nov. 6, 1998, all of which are hereby incorporated by reference herein in their entireties.
In view of the foregoing, it is an object of this invention to provide apparatus that can be used to make anastomotic connections in lieu of manual suturing.
It is another object of the invention to provide apparatus that can be used to make anastomotic connections even though access to the site of the anastomosis may be limited or even only indirect or remote.
It is still another object of the invention to provide apparatus that can be used to make anastomotic connections without the need for a high degree of manual suturing skill.
It is yet another object of the invention to provide apparatus for making anastomotic connections that is less adversely affected than manual suturing by adjacent or nearby body motion (e.g., motion of the patient""s heart).
It is still another object of this invention to provide apparatus for facilitating the making of higher quality anastomotic connections more rapidly and with more consistent results than is possible with prior art methods and apparatus such as manual suturing.
These and other objects of the invention are accomplished in accordance with the principles of the invention by providing a connector for use in making an anastomotic connection between two tubular body fluid conduits in a patient, the connector being of substantially one-piece or unitary construction which extends annularly about a central longitudinal axis. The structure of the connector includes axially spaced first and second portions, at least one of which includes members that are deflectable radially out from a remainder of the connector structure. In some embodiments both of the axially spaced first and second portions include members that are deflectable radially out from a remainder of the structure. The connector structure is annularly enlargeable, preferably by inflation of a balloon placed temporarily inside the connector. The structure of the connector preferably lends itself to formation by removal of selected material from a single unitary tube. The connector is typically made of metal which is plastically deformable (e.g., in the above-mentioned radial outward deflections and annular enlargement).
The members that are deflectable radially out from the first portion of the connector structure are configured to engage the side wall of one of the two tubular body fluid conduits that are to be connected. The members that are deflectable radially out from the second portion of the connector structure are configured to engage the side wall of the other of the two body fluid conduits that are to be connected. Alternatively, one of the two portions of the connector can be secured (preferably pre-secured) to the associated conduit by other means such as sutures. Annular expansion of the connector preferably causes the first and second portions of the connector structure to move toward one another along the central longitudinal axis of the connector, thereby causing the connector to draw the two tubular body fluid conduits together at the anastomosis between them. This helps produce an anastomosis which is fluid-tight (i.e., from which body fluid does not leak).
The connectors of this invention can be used to provide either end-to-side or side-to-side anastomoses. The connector may be first attached to one of the body fluid conduits to be connected (e.g., an end portion of a graft conduit), and then delivered along with the attached end of the first conduit to the connection point with the second conduit, where the connector is fully deployed to produce an anastomosis between the first and second conduits. Prior to full deployment the connector preferably has a relatively small circumference, which facilitates delivery and initial installation in the patient, even at relatively remote or inaccessible locations in the patient. For example, the connector can be delivered via lumens of body fluid conduits in the patient and/or relatively small-diameter instrumentation such as a cannula or laparascopic-type device. Final installation can be performed substantially solely by inflation of a balloon temporarily disposed in the connector. No direct manipulation of the connector may be needed. All of these attributes facilitate use of the connector at remote or inaccessible locations in the patient. The connector therefore lends itself to use in less invasive or minimally invasive procedures.
Instrumentation for facilitating installation of the connector through the side wall of a body fluid conduit is also disclosed. This instrumentation has a gradually tapered distal nose portion with an outer surface that is free of features that could snag on the side wall of the body fluid conduit to be penetrated by the nose portion. At least the portion of the connector that must pass through the body fluid conduit side wall is completely covered by the instrumentation until that portion of the connector is through the side wall. These features of the instrumentation help it penetrate the body fluid conduit side wall with no snagging and with minimal trauma. Thereafter the distal nose portion can be shifted distally relative to the connector to expose the connector in position through the side wall. Other parts of the instrumentation (e.g., an inflatable balloon) can then be operated to complete the deployment of the connector.
Further features of the invention, its nature and various advantages will be more apparent from the accompanying drawings and the following detailed description of the preferred embodiments.